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The fine print

Boomers get bummed when it's time for reading glasses. Luckily, there are lots of ways to improve aging vision.

If you're younger than 40, you can probably turn the page without fear - for now. After age 40, most people develop presbyopia, a vanity-crushing condition in which one's eyes no longer focus nimbly on objects close at hand.

Reading glasses and bifocals: It's a middle-age thing. But today, at least, there are more choices in ways to see close-up.

Presbyopia usually begins in the early or middle 40s and affects most people by age 50. Over the years, the lens of the eye - that clear, disklike structure behind the iris that changes shape to permit distant or near vision - gets progressively thicker and less elastic. Eventually, the lens can no longer properly focus onto the retina the light rays coming from close-up objects. To compensate, we hold books and other objects farther and farther away.

Even with presbyopia, moderately nearsighted people can still see close objects clearly if they remove their glasses or contacts, though that's not a long-term solution.

The cheapest and simplest remedy is reading glasses for those who have good distance vision or who wear contacts. The drugstore kind are fine unless you have significant astigmatism. Pick the lowest strength at first and graduate to stronger ones, if needed. They do the job, but vanity-wise, they're not so great.

Neither are bifocals. These eyeglasses correct for distance and near vision in the same lens, separated by a discernable line. That's why a lot of people pay more for progressive power or no-line bifocals, which gradually become stronger toward the bottom of the lenses. But in addition to costing more, they have optical drawbacks: They have a "sweet spot," like a tennis racket, where vision is sharpest, but other areas are a little blurry, says Dr. David Guyton, a professor of ophthalmology at Johns Hopkins School of Medicine in Baltimore.

Another option is trifocals, either the traditional kind with lines or with progressive lenses. They include a third, middle zone, designed to help with computer screens, piano music, and other middle-distance tasks.

Contact lenses have the virtue of invisibility, but, like all the strategies, have their own set of trade-offs. With presbyopia, there's no free lunch. With contacts, there are two ways to go: monovision lenses or bifocal lenses. With monovision, the optometrist prescribes one lens for close-up vision and the other for distant viewing. Usually, the dominant eye gets the stronger lens and the non-dominant eye the weaker one. Your brain, amazingly, usually gets accustomed in no time to using, say, the left eye for reading and the right for driving.

There's some loss of depth perception with monovision contacts. And - a compromise again - neither close-up nor distant objects are quite as sharp as they would be if both eyes were corrected either for near vision or far vision. Even so, about 75 percent of people who try monovision contacts are comfortable with them, says Ronald Watanabe, chief of contact lens services at the New England College of Optometry in Boston.

Although they've been around for years, bifocal contacts haven't been widely accepted. They're more expensive, and until the past few years, says Watanabe, the quality of vision correction left a lot to be desired. New techniques have improved the contacts, and bifocal versions are now available in soft lenses or rigid gas-permeable lenses.

Some types of bifocal contacts have a central area with one prescription surrounded by a ring of the contrasting strength, while others have an upper and lower zone, as with bifocal glasses. But, as with monovision contacts, neither version is perfect. "There is some softness to whatever you look at," says Watanabe.

Most of the bifocal contacts sold today are disposable soft lenses, costing $350 to $400 for a year's supply, compared with $150 or $200 for standard disposables. Gas-permeable lenses, because they're made of harder plastic, take getting used to. But, for the same reason, their optical quality is better, and vision is sharper.

As with monovision contacts, choosing bifocal contacts means giving up expectations of perfection, Watanabe stresses. "A few patients see just great, but if they're expecting their vision to be as good as with bifocal glasses," he says, they will be disappointed.

They will also be disappointed if they expect refractive surgery, like PRK or LASIK, to correct presbyopia. It doesn't do that. Unless they have monovision (having one eye corrected for distance and the other for close-up) etched into their corneas with the laser, they will still need to have reading glasses. But if they choose this option, there's no going back - the laser surgery can't be undone.

Finally, a few eye surgeons are experimenting with a new operation that seems to correct presbyopia in some patients. It's called scleral expansion, and it works according to a theory of presbyopia that's controversial. According to this theory, as the eye's lens grows larger over time, it becomes crowded by the curve of the eyeball and can't accommodate close-up vision.

In scleral expansion surgery, four tiny pieces of plastic are inserted into the white part of the eye at equidistant points. These inserts expand the eye surface outward and ease the crowding of the lens. A federally funded trial of the procedure is underway. Johns Hopkins's Guyton says that until those results are in and it gets federal approval, he will not recommend the operation.

But even without this possibly groundbreaking surgery, there are enough ways to deal with presbyopia today to satisfy all but the most demanding of aging baby boomers.